Process For Surfactant Taste And/Or Odor Improvement

ABSTRACT

Processes for improving the taste of water-soluble surfactants using liquid-liquid solvent extraction, said process comprising the steps of: providing a water-soluble surfactant composition in need of treatment wherein said water-soluble surfactant composition comprises a water-soluble surfactant and one or more undesirable non-polar materials; contacting said water-soluble surfactant composition with an extraction solvent and water to form an extraction mixture comprising an aqueous phase and a solvent phase; and separating the aqueous phase from the solvent phase; wherein the extraction solvent is selected from solvents having individual Hansen solubility parameters of a dispersion force component (δ D ) ranging from about 15 to about 17 (MPa) 0.5 , a polar component (δ P ) ranging from 0 to about 9 (MPa) 0.5  and a hydrogen bonding component (δ H ) ranging from 0 to about 11 (MPa) 0.5 . Treated water-soluble surfactant compositions produced by such processes and oral care compositions containing such treated water-soluble surfactant compositions.

FIELD OF THE INVENTION

The present invention relates to water-soluble surfactant compositionscontaining undesirable non-polar materials and liquid-liquid extractionprocesses for improving the taste and/or odor of such compositions.

BACKGROUND OF THE INVENTION

Traditionally, much effort has been expended to improve the taste,color, odor or clarity of oral care compositions such as dentifrice(toothpaste), mouth rinse, and the like. Because of the nature of suchcompositions, the taste of a product may often be of more importance toconsumers than the actual or perceived efficacy. Since many efficaciousoral care components have undesirable taste, color, odor or clarity,efforts to improve these characteristics are common in the art. Fortaste, one way to remedy an undesirable product taste is to addadditional components, such as flavors, that will improve the overalltaste experience for the consumer. However, such remedies can beexpensive and it may be difficult to entirely mask an undesirable taste.Improvement of color or clarity through dyes or other additives hassimilar issues.

Water-soluble surfactants such as alkyl phosphate surfactants arecommercially available for use in a variety of consumer products,including oral care compositions. These anionic surface activeorganophosphate agents have a strong affinity for enamel surface andhave sufficient surface binding propensity to desorb pellicle proteinsand remain affixed to enamel surfaces. Such properties make thesematerials desirable for incorporation in oral care compositions such astoothpaste. However, these materials have not been widely commercializedin oral care compositions, despite their desirable properties. Onereason for this lack of commercialization may be the negative tasteand/or odor profile commonly associated with commercially availablealkyl phosphate materials. Although taste may not be a consideration inother consumer product industries, such as laundry, shampoo or personalcleansing, it is an important consideration in oral care. Similarly,while any undesirable odor associated with materials used in laundry,shampoo or personal cleansing products can typically be remedied by theaddition of perfume, perfume levels must be kept to a minimum in oralcare compositions for consumer acceptance and could produce furtherunpleasant tastes when utilized.

Purification of surfactant materials through steam-stripping,vacuum-stripping, and/or carbon filtration processes is also generallyknown to beneficially remove impurities to increase efficacy, minimizeundesirable side reactions, and the like. However, these purificationprocesses have been found to be insufficient to remedy the unpleasanttastes and/or odors associated with commercially available water-solublesurfactant materials.

Liquid/liquid extractions (LLE) are generally known in the art as usefulfor separating components of a mixture, wherein the constituents havediffering polarities which can be separated when mixed within twoimmiscible solvents that form a liquid bilayer after mixing. Forexample, LLEs are useful for purifying or cleaning samples which containimpurities of significantly differing polarity than the majority ordesirable component(s) of the sample. This can be achieved by mixing asample with a solvent that is immiscible with the primary liquid inwhich the sample is dissolved.

LLE has been utilized in chemical processing to reduce or eliminateundesirable by-products or contaminants. For instance, PCT PatentApplication WO 2008005550 to Hoke, et al (Procter & Gamble) discloses awater washing procedure to remove polar sulfur impurities frompeppermint oils to avoid malodor formation when formulated in dentifricecontaining stannous ions. In U.S. Pat. No. 4,352,829 to Noyes, et al(Procter & Gamble) an ethyl acetate extraction of caffeine from coffeewas shown to be an effective decaffeination process.

However, there is still an interest in finding ways to improve theoverall taste and/or odor of water-soluble surfactants such as thoseused in an oral care composition that are efficacious, cost-effective,and desirable to consumers.

SUMMARY OF THE INVENTION

It has now surprisingly been found that liquid-liquid extractionprocesses utilizing solvents such as ethyl acetate may be useful tosignificantly reduce the occurrence of non-polar materials found inwater-soluble surfactant raw materials and thereby improve thesurfactant's odor and/or taste profile.

Without being limited by theory, it is now believed that water-solublesurfactants previously generally thought to have bad taste and/or odorprofiles stemming from the pure material itself are in fact surprisinglyacceptable in terms of taste and odor. It has been surprisingly foundthat non-polar materials commonly present in commercially availablewater-soluble surfactant compositions such as residual alcohols, alcoholethoxylates, aldehydes, ethers, ketones, alkylamines, and esters, may belinked to the majority of the negative taste and odor profilespreviously associated with the surfactants themselves. Since some ofthese materials are often used in flavors and perfumes, it was furthersurprising that a new process for more efficiently extracting thesematerials from the underlying surfactant would produce such results. Forexample, dodecanol and dodecanal are commonly taught to be safe anduseful for inclusion in flavors and perfumes, yet it has beensurprisingly found that if included in water-soluble surfactantcompositions at significantly higher levels, these materials present anunpleasant taste such as bitter, soapy and the like.

Further without being limited by theory, liquid-liquid extraction usingthe appropriate solvent is more effective than previously knowntechniques to purify such surfactants, allowing for the incorporation ofsuch surfactants into oral care products with minimal negative tasteand/or odor attributes.

The present invention is therefore directed to a process or method ofimproving the taste and/or odor of water-soluble surfactants usingliquid-liquid solvent extraction.

In one embodiment, the present invention relates to a process or methodfor improving the taste of water-soluble surfactants using liquid-liquidsolvent extraction, said process comprising the steps of: providing awater-soluble surfactant composition in need of treatment wherein saidwater-soluble surfactant composition comprises a water-solublesurfactant and one or more undesirable non-polar materials; contactingsaid water-soluble surfactant composition with an extraction solvent andwater to form an extraction mixture comprising an aqueous phase and asolvent phase; and separating the aqueous phase from the solvent phase;wherein the extraction solvent is selected from solvents havingindividual Hansen solubility parameters of a dispersion force component(δ_(D)) ranging from about 15 to about 17 (MPa)^(0.5), a polar component(δ_(P)) ranging from 0 to about 9 (MPa)^(0.5) and a hydrogen bondingcomponent (δ_(H)) ranging from 0 to about 11 (MPa)^(0.5).

In another embodiment, the present invention relates a process or methodfor improving the taste of water-soluble surfactants using liquid-liquidsolvent extraction, said process comprising the steps of: providing awater-soluble surfactant composition comprising a surfactant selectedfrom alkyl phosphate surfactants, alkyl phosphate ethoxylatedsurfactants, and mixtures thereof and one or more undesirable non-polarmaterials; contacting said water-soluble surfactant composition withethyl acetate and water to form an extraction mixture comprising anaqueous phase and a solvent phase; and separating the aqueous phase fromthe solvent phase.

In another embodiment, the present invention relates to such processesor methods wherein the water-soluble surfactant is at least about 20%soluble in water.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the water-soluble surfactant is selectedfrom anionic surfactants, zwitterionic surfactants, amphotericsurfactants, and mixtures thereof and is at least about 30% soluble inwater.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the water-soluble surfactant is selectedfrom alkyl phosphate surfactants, alkyl phosphate ethoxylatedsurfactants, lauryl sulfate surfactants, betaine surfactants, betaineethoxylated surfactants, amine oxide surfactants, and mixtures thereof.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the surfactant is selected fromcocoamidopropyl betaines, lauryl betaines, capryl/capramidobetaines,sodium lauryl sulfates, mono alkyl phosphates, amine oxides, andmixtures thereof.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the water-soluble surfactant is selectedfrom cocoamidopropyl betaine surfactants, mono alkyl ethoxylatedphosphate surfactants, mono alkyl phosphate surfactants, and mixturesthereof. In one embodiment, the water-soluble surfactant is an alkylethoxylated phosphate surfactant.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the extraction solvent has individualHansen solubility parameters of a dispersion force component (δ_(D))ranging from about 13 to about 19 (MPa)^(0.5), a polar component (δ_(P))ranging from about 2 to about 9 (MPa)^(0.5) and a hydrogen bondingcomponent (δ_(H)) ranging from about 2 to about 11 (MPa)^(0.5).

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the extraction solvent is selected fromethyl acetate, water-saturated ethyl acetate, ethyl propionate, ethylbutyrate, ethyl pentanoate, ethyl caproate, ethyl caprylate, ethylpelargonate methyl acetate, methyl propionate, methyl butyrate, shortchain esters and mixtures thereof.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the extraction solvent is selected fromfood grade ethyl esters.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the extraction solvent is ethyl acetate.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the extraction mixture comprises from about10% to about 90%, by weight of the mixture, of water; from about 5% toabout 60%, by weight of the mixture, of water-soluble surfactant; lessthan 5%, by weight of the mixture, of undesirable non-polar impurities;and from about 10% to about 90%, by weight of the mixture, of solvent.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the ratio of extraction solvent towater-soluble surfactant in the extraction mixture is from about 1:10 toabout 10:1.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the ratio of extraction solvent towater-soluble surfactant in the extraction mixture is from about 1:2 toabout 2:1.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the step of separating the aqueous phasefrom the solvent phase further comprises centrifuging the extractionmixture.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the process further comprises mixingextraction mixture is mixed for a period of from about 10 seconds toabout one minute with vigorous mixing and at ambient temperature beforeallowing the mixture to settle into two phases and separating theaqueous phase from the solvent phase.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the process further comprises the step ofheating a solid impure surfactant material to its melting point beforethe step of contacting with an extraction solvent and water.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the process further comprises the step ofremoving any residual solvent from the aqueous phase.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the step of removing any residual solventfrom the aqueous phase includes the use of an industrial method selectedfrom vacuum stripping (with or without heat), wiped-film evaporationfractional distillation, carbon filtration, or combinations thereof.

In another embodiment, the present invention relates to the aboveprocesses or methods wherein the extraction mixture further comprises aphase separation enhancer selected from salt, pH modifiers, and mixturesthereof.

In another embodiment, the present invention relates to a treatedwater-soluble surfactant composition resulting from the above processesor methods comprising from about 10% to about 70% of water-solublesurfactant, from about 30% to about 90% water, and less than about 1% ofundesirable non-polar materials, produced by the processes set forthabove.

In another embodiment, the present invention relates to such surfactantswherein the surfactant comprises less than about 0.5% of undesirablenon-polar materials.

In another embodiment, the present invention relates to such surfactantswherein the surfactant comprises less than about 1% of total alcohols.

In another embodiment, the present invention relates to a treated monoalkyl phosphate surfactant produced by the processes or methods setforth above.

In another embodiment, the present invention relates to a treatedcocoamidopropyl betaine surfactant produced by the processes or methodsset forth above.

In another embodiment, the present invention relates to an oral carecomposition having improved consumer acceptance, wherein the oral carecomposition comprises a water-soluble surfactant composition treated bythe processes set forth above

In another embodiment, the present invention relates to use ofliquid-liquid solvent extraction for improving the taste ofwater-soluble surfactants wherein ethyl acetate is used as an extractionsolvent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of a process for purifying surfactants usingliquid-liquid solvent extraction in accordance to one embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a process for improving the taste ofwater-soluble surfactants using liquid-liquid solvent extraction. Theprocess includes the steps of:

-   -   a) providing a water-soluble surfactant composition in need of        treatment wherein said water-soluble surfactant composition        comprises a water-soluble surfactant and one or more undesirable        non-polar materials;    -   b) contacting said water-soluble surfactant composition with an        extraction solvent and water to form an extraction mixture        comprising an aqueous phase and a solvent phase; and    -   c) separating the aqueous phase from the solvent phase;        wherein the extraction solvent is selected from solvents having        individual Hansen solubility parameters of a dispersion force        component (δ_(D)) ranging from about 15 to about 17 (MPa)^(0.5),        a polar component (δ_(P)) ranging from 0 to about 9 (MPa)^(0.5)        and a hydrogen bonding component (δ_(H)) ranging from 0 to about        11 (MPa)^(0.5). The present invention further relates to        improved water-soluble surfactant compositions produced by the        processes herein and oral care compositions containing such        improved surfactants.

These elements will be discussed in more detail below.

Process for Improving the Taste of Water-Soluble Surfactants

As used herein, liquid-liquid extraction, also known as solventextraction and partitioning, refers to a standard method to separatecompounds based upon their relative solubilities in two differentimmiscible liquids, here, water and a solvent. It is an extraction of asubstance from one liquid phase into another liquid phase. The“liquid-liquid” phrase refers to the two different immiscible liquidsthat are mixed as part of the extraction procedure. As used herein,immiscible refers to the ability of the two liquids to form at least twolayers when mixed together. The layers may be formed after mixing thetwo liquids and allowing them to sit at rest for a variable period oftime, or in some instances, the mixture of the two liquids may becentrifuged and/or cooled below room temperature in order to assist theseparation.

Typically in liquid-liquid extraction, one of the phases will beaqueous, and the other a non-polar lipophilic organic solvent such asether, MTBE, dichloromethane, chloroform, or ethyl acetate. Most organicsolvents float on top of an aqueous phase, though important exceptionsare most halogenated solvents.

Equipment typically used in a laboratory setting for liquid-liquidextraction includes a separatory funnel. In a small scale plant or lab,batch-wise liquid-liquid extraction methods may be used, such as bymixing the two liquids and then introducing them into a large scaleseparatory funnel. In larger scale plant production, a multistagecontinuous counter current extractor may be used to quickly and easilyrun multiple extractions in sequence. In one embodiment, the processincludes the use of a machine selected from centrifugal contactors, thinlayer extractors, spray columns, pulsed columns, and mixer-settlers, andcombinations thereof, in the extraction process.

In many instances, a separatory funnel has the shape of a conesurmounted by a hemisphere. It has a stopper at the top and stopcock(tap), at the bottom. Separating funnels used in laboratories aretypically made from borosilicate glass and their stopcocks are made fromglass or PTFE. Typical sizes are between 50 mL and 3 L. In industrialchemistry they can be much bigger and for much larger volumes,centrifuges are used.

To use a separatory funnel, the extraction mixture is introduced intothe separatory funnel through the top with the stopcock at the bottomclosed. The funnel is then closed and shaken gently by inverting thefunnel multiple times. The funnel is then inverted and the tap carefullyopened to release excess vapor pressure. The separating funnel is setaside to allow for the complete separation of the phases. The top andthe bottom tap are then opened and the two phases are individuallyreleased by gravitation and separately captured.

Referring now to FIG. 1, an industrial flow chart detailing the process10 of making a water-soluble surfactant and then improving the taste ofwater-soluble surfactants using liquid-liquid extraction, contains aseries of steps, step 20 providing fresh surfactant raw materialstarting materials, step 30 production of the water-soluble surfactantthrough traditional means, step 40 quenching the reaction, step 50optional intermediate processing and/or cleanup and providing thewater-soluble surfactant composition in need of treatment, step 60contacting the water-soluble surfactant composition with an extractionsolvent, and water step 70 to form an extraction mixture containing anaqueous phase and a solvent phase, step 80 separating the liquid phaseswith optional centrifuge and optional repeating of steps 60 and 70, step90 separating residual volatile solvent from the aqueous phase by meanssuch as vacuum stripping, heating, wiped-film evaporation orcombinations thereof, step 100, collecting the improved water-solublesurfactant, step 110 conducting fractional distillation on the organicphase to, step 120 recover the extraction solvent for future use, step130 to collect non-polar materials (impurities) and separate intovaluable and 140 unusable non-polar materials (impurities) including thestep of 150 recovering the starting surfactant raw materials for reuse.

At step 20 and 30, the water-soluble surfactant raw material, such asthose commercially available, is produced. At step 60, the process forimproving the taste of such water-soluble surfactant raw material beginsby providing the water-soluble surfactant composition in need oftreatment wherein the water-soluble surfactant composition contains awater-soluble surfactant and one or more undesirable non-polarmaterials. By combining the water-soluble surfactant composition withwater and solvent forming an extraction mixture and then separating theaqueous phase from the solvent phase in step 80, the treatedwater-soluble surfactant may be collected, in step 100.

In one embodiment, the liquid-liquid extraction process will use anextraction step in which undesirable non-polar materials are transferredfrom the aqueous phase to the solvent phase and then optionally followedby a scrubbing stage in which the undesirable non-polar materials areremoved from the solvent phase, then optionally followed by a strippingstage in which any water-soluble surfactants or other materials areremoved from the solvent phase. The solvent phase may then be treated tomake it ready for use again.

In one embodiment, the process includes a step of collecting thewater-soluble surfactant from the aqueous phase. In another embodiment,after the step of collecting the water-soluble surfactant from theaqueous phase, the water-soluble surfactant is subjected to one or moreof the following:

-   -   a) at least one repeat of the process steps, optionally        repeating the steps of the process at least 3 times, optionally        repeating the steps of the process at least 4 times, in        succession;    -   b) a further filtration step, optionally using carbon        filtration; and/or    -   c) incorporation of the water-soluble surfactant into an oral        care composition.

Procedure for Optimizing pH in Preparation for Liquid/Liquid Extraction

In one embodiment, the process further comprises a step of optimizingthe pH of the extraction mixture. In such a step, the solubility of thewater-soluble surfactant composition may be optimized and the polaritydifference between the desirable water-soluble surfactant andundesirable non-polar materials that are imparting negative aroma, tasteand/or color may be maximized. The pH is an important variable that canbe adjusted to maximize the polarity difference between the desirablewater-soluble surfactant and the undesirable non-polar materials. Thisis especially important with classes of compounds that can change fromprimarily charged to neutral state and vice versa by pH manipulation.

For example, in the case of mono alkyl phosphate surfactants, a higherpH may be preferable to ensure that the phosphate groups are largely inthe ionized state, thereby maximizing polarity and water solubility. Atthe same time, most of the undesirable non-polar materials found incommercially-available MAP compositions would not be significantlyionized at typical pHs, and possess a net hydrophobic character, so inone embodiment, the pH during extraction is optimized to be in the rangeof 8-11. In one embodiment, the process further comprises an extractionpH of from about 8 to about 11, alternatively from 8 to 10.

Further, a consideration is to avoid pHs that can initiate chemicalreactivity, for a given extraction mixture comprising an aqueous phasecomprising a water-soluble surfactant raw material dissolved in water,an undesirable non-polar material, and the extraction solvent. Forexample, when using ethyl acetate as an extraction solvent with monoalkyl phosphate, it is recommended to maintain extraction conditions ina pH range that will avoid converting EtOAc to acetic acid and ethanol.In one embodiment, after extraction, the ethyl acetate should be removedto a level that will be odorless and also avoid the potential for laterconversion to significant levels of ethanol and acetic acid, the latterof which may introduce vinegar odors into the raw material. In oneembodiment, after extraction, the ethyl acetate is removed to a level ofless than 50 ppm, alternatively less than 5 ppm.

General pH optimization can be performed as above. For refined pHoptimization, adjust pH in small increments and perform a single stageLLE. After single extractions over the target pH range, analyticallymeasure the amount of water-soluble surfactant and the amount ofundesirable non-polar materials in the extraction solvent, with priorknowledge of the starting concentrations of surfactant and non-polarimpurities in the water-soluble surfactant composition. Identify the pHrange where the impurity removal into the solvent phase is optimal andthe surfactant retention in the aqueous phase is also optimal.

Providing a Water-Soluble Surfactant Composition in Need of Treatment

Water-Soluble Surfactant

As used herein “water-soluble surfactant” refers to those surfactantsthat are at least partially soluble in water, when measured at roomtemperature (25° C.). In one embodiment, the water-soluble surfactant isat least 10% soluble in water, alternatively is at least 20% soluble inwater, still alternatively is at least 30% soluble in water,alternatively at least 40% soluble in water. As used herein in arelative sense, “water-soluble surfactant raw material” refers to thewater-soluble surfactant itself, absent significant levels of water orundesirable by-products or starting materials such as those found in“water-soluble surfactant compositions” as described further below.Further, as used herein, “extracted water-soluble surfactantcomposition” or “treated water-soluble surfactant composition” refers towater-soluble surfactant compositions that have undergone the processesset forth herein and have some measurable level of reduction inundesirable non-polar materials versus the untreated water-solublesurfactant compositions.

As used herein, “in need of treatment” means that the water-solublesurfactant composition contains levels of undesirable non-polarmaterials higher than what is needed for a particular product usage. Fororal care compositions, water-soluble surfactant compositions in need oftreatment include those water-soluble surfactant compositions containingabout 0.01% or more, by weight of the composition, of undesirablenon-polar materials, alternatively containing more than about 0.1%,alternatively more than about 0.5%, alternatively more than about 0.7%,alternatively 1% or more, by weight of the composition, of suchmaterials.

Identifying a Suitable Water-Soluble Surfactant

In one embodiment, the process herein includes the step of identifying asuitable water-soluble surfactant. The step of identifying a suitablewater-soluble surfactant may include the sub-step of determining thesurfactant's water solubility. When determining the surfactant's watersolubility, conditions should be optimized for solubilizing thesurfactant in water, as well as for minimizing the amount of thedesirable raw material that could be extracted into the solvent phasealong with the undesirable, relatively non-polar impurities. The pH maybe adjusted so that charge will persist on suitable surfactants that aresubject to ionization via pH manipulation in a typical pH range.Temperature can be raised, if needed, and samples should be vigorouslyshaken and/or stirred to facilitate formation of a homogenous solution.If a surfactant is aqueous soluble at roughly 10% or greater, then it isa good candidate for taste/odor/color cleanup by LLE to removeless-polar undesirable compounds.

To evaluate a surfactant, whose water solubility is in question, place10 g solid surfactant into a glass vessel and add 100 mL of distilled,deionized water. Raise the temperature up to 60° C. (or higher if themelting point is higher), if needed, and shake, stir, or vortex, asappropriate, for up to 30 minutes. If all of the raw material isdissolved, creating a clear solution, then it is suitable for use in theprocesses set forth herein. For objective evaluation of solubility,after heating and stirring, vacuum filter through a membrane with 10 umpore size. Weigh solid material recovered on the filter to determine ifa significant amount of surfactant remains undissolved. If needed forconfirmation, utilize a direct analytical measure of the concentrationof the material that is dissolved in the clear aqueous portion viaappropriate analytical method.

Examples of water-soluble surfactants that may be purified by theprocesses herein include cocoamidopropyl betaines, lauryl betaines,capryl/capramidobetaines, sodium lauryl sulfates, mono alkyl phosphates,amine oxides, and mixtures thereof.

Water-soluble surfactants useful herein may, in some embodiments beselected from anionic surfactants such as alkyl phosphates. Thesesurface active organophosphate agents have a strong affinity for enamelsurface and have sufficient surface binding propensity to desorbpellicle proteins and remain affixed to enamel surfaces. Suitableexamples of organophosphate compounds include mono-, di- or triestersrepresented by the general structure below wherein Z1, Z2, or Z3 may beidentical or different, at least one being an organic moiety, in oneembodiment selected from linear or branched, alkyl or alkenyl group offrom 1 to 22 carbon atoms, optionally substituted by one or morephosphate groups; alkoxylated alkyl or alkenyl, (poly)saccharide, polyolor polyether group.

Some other agents include alkyl or alkenyl phosphate esters representedby the following structure:

wherein R1 represents a linear or branched, alkyl or alkenyl group offrom 6 to 22 carbon atoms, optionally substituted by one or morephosphate groups; n and m, are individually and separately, 2 to 4, anda and b, individually and separately, are 0 to 20; Z2 and Z3 may beidentical or different, each represents hydrogen, alkali metal,ammonium, protonated alkyl amine or protonated functional alkyl aminesuch as an alkanolamine, or a R1-(OCnH2n)a(OCmH2m)b-group. Examples ofsuitable agents include alkyl and alkyl(poly)alkoxy phosphates such aslauryl phosphate; PPG5 ceteareth-10 phosphate; Laureth-1 phosphate;Laureth-3 phosphate; Laureth-9 phosphate; Trilaureth-4 phosphate; C12-18PEG 9 phosphate; Sodium dilaureth-10 phosphate. In one embodiment, thealkyl phosphate is polymeric. Examples of polymeric alkyl phosphatesinclude those containing repeating alkoxy groups as the polymericportion, in particular 3 or more ethoxy, propoxy isopropoxy or butoxygroups.

Zwitterionic or amphoteric surfactants useful in the present inventioninclude derivatives of aliphatic quaternary ammonium, phosphonium, andsulfonium compounds, in which the aliphatic radicals can be straightchain or branched, and wherein one of the aliphatic substituentscontains from about 8 to 18 carbon atoms and one contains an anionicwater-solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphateor phosphonate. Suitable amphoteric surfactants include betainesurfactants such as disclosed in U.S. Pat. No. 5,180,577 to Polefka etal. Typical alkyl dimethyl betaines include decyl betaine or2-(N-decyl-N,N-dimethylammonio)acetate, coco betaine or2-(N-coco-N,N-dimethyl ammonio)acetate, myristyl betaine, palmitylbetaine, lauryl betaine, cetyl betaine, stearyl betaine, etc. Theamidobetaines are exemplified by cocoamidoethyl betaine, cocamidopropylbetaine (CAPB), and lauramidopropyl betaine. The unwanted tastes oftenassociated with these surfactants are soapy, bitter, chemical, and/orartificial.

Additional suitable polymeric organophosphate agents include dextranphosphate, polyglucoside phosphate, alkyl polyglucoside phosphate,polyglyceryl phosphate, alkyl polyglyceryl phosphate, polyetherphosphates and alkoxylated polyol phosphates. Some specific examples arePEG phosphate, PPG phosphate, alkyl PPG phosphate, PEG/PPG phosphate,alkyl PEG/PPG phosphate, PEG/PPG/PEG phosphate, dipropylene glycolphosphate, PEG glyceryl phosphate, PBG (polybutylene glycol) phosphate,PEG cyclodextrin phosphate, PEG sorbitan phosphate, PEG alkyl sorbitanphosphate, and PEG methyl glucoside phosphate. Suitable non-polymericphosphates include alkyl mono glyceride phosphate, alkyl sorbitanphosphate, alkyl methyl glucoside phosphate, alkyl sucrose phosphates.The unwanted tastes often associated with these surfactants are soapy,chemical, and/or artificial.

Water-soluble amphoteric surfactants useful herein further include amineoxide surfactants Amine oxides are the result of oxidation of tertiaryamines, typically C12-C18 alkyl dimethyl, N-oxides. For example, amineoxide surfactants useful herein may include lauryl dimethyl amine oxide;lauryl dihydroxyethyl amine oxide; cocamidopropyl amine oxide;Lauramidopropylamine oxide; cetyl dimethyl amine oxide;3-Lauramidopropyl-N,N-dimethylamine oxide.

Water-soluble cationic surfactants useful in the present inventioninclude derivatives of quaternary ammonium compounds having one longalkyl chain containing from about 8 to 18 carbon atoms such as lauryltrimethylammonium chloride; cetyl pyridinium chloride; cetyltrimethylammonium bromide; coconut alkyltrimethylammonium nitrite; cetylpyridinium fluoride; etc. Preferred compounds are the quaternaryammonium halides having detergent properties described in U.S. Pat. No.3,535,421 to Briner et al. Certain cationic surfactants can also act asgermicides in the oral care compositions disclosed herein.

In another embodiment, the water-soluble surfactant is selected fromanionic surfactants, zwitterionic surfactants, amphoteric surfactants,cationic surfactants, nonionic surfactants and mixtures thereof. In oneembodiment, the water-soluble surfactant is selected from alkylphosphate surfactants, alkyl phosphate ethoxylated surfactants, laurylsulfate surfactants, betaine surfactants, betaine ethoxylatedsurfactants, amine oxide surfactants, and mixtures thereof. In anotherembodiment, the water-soluble surfactant is selected from alkylphosphate surfactants, alkyl phosphate ethoxylated surfactants, andmixtures thereof. In one embodiment, the water-soluble surfactant is amono alkyl phosphate surfactant.

In one embodiment, the surfactant is selected from cocoamidopropylbetaines, alkyl ethoxylated phosphates, mono alkyl phosphates, andmixtures thereof.

Water-Soluble Surfactant Composition

The water-soluble surfactant compositions disclosed herein contain awater-soluble surfactant and one or more undesirable non-polarmaterials. Water-soluble surfactant compositions useful herein includethose commercially available from suppliers such as Rhodia (located inSpartanburg, S.C., USA), Stepan (located in Metamoros, Mexico andWinder, Ga., USA), Croda (located in Edison, N.J., USA) and Clariant(located in Charlotte, N.C., USA). Without being limited by theory, thepresence of the undesirable non-polar materials are what present thesecompositions as being in need of treatment, e.g., the compositions arein need of removing such undesirable materials. Further without beinglimited by theory, it has been surprisingly found that currentcommercially available water-soluble surfactants, although purified tovarying degrees by the manufacturers before sale, still containsignificant amounts of undesirable non-polar materials that affect tasteand/or color of the water-soluble surfactant raw material.

These undesirable non-polar materials may be unreacted startingmaterials used in the manufacturing of the surfactants (such as alcoholand/or amines), the products of side reactions occurring during themanufacturing process, or oxidation products (such as aldehydes).

The water-soluble surfactant composition may further comprise from about0.1% to about 90% water, alternatively from about 10% to about 50%, byweight of the composition, of water. Typically water-soluble surfactantsare commercially available as aqueous mixtures. The water may be removedin part or in whole from the water-soluble surfactant composition beforeconducting the liquid-liquid extraction processes of the presentinvention. Where the water is removed in large degree from thecommercially available composition, it may be necessary to reintroducewater into the process as part of the extraction mixture.

Many commonly used water-soluble surfactant raw materials are producedby commercial suppliers as aqueous solutions at fairly highconcentrations. These surfactants are good candidates for odor, color,and/or taste improvement by liquid-liquid extraction according to theprocesses set forth herein.

Water-soluble alkyl phosphate surfactant compositions that may beimproved by the processes set forth herein include commerciallyavailable compositions shown in Table 1:

TABLE 1 Concen- tration (in Aver- Trade- aqueous EO age Supplier nameAlkyl Chain solution) Salt # MW Croda 230K Mono Laureth 40% Potas- 0266.317 sium Rhodia L204K Mono Laureth 20% Potas- 0 266.317 sium RhodiaL213/S Mono Laureth 30% Sodium 1 310.3712 Clariant 340D Di Laureth 40%none 4 442.5305 Rhodia L130 Mono Laureth 100%  none 3 398.4774 RhodiaL190 Mono Laureth 100%  none 9 662.7968

Undesirable Non-Polar Materials

As used herein “undesirable non-polar materials” refers generally to anynon-polar materials that are found in the water-soluble surfactantcomposition in need of treatment. In one embodiment, the undesirablenon-polar materials are selected from residual alcohols, alcoholethoxylates, aldehydes, ethers, ketones, alkylamines, amides, andesters.

In one embodiment, the undesirable non-polar materials may beoff-tasting components selected from impurities, unreacted startingmaterials, by-products and/or contaminants. Such undesirable non-polarmaterials may be described by consumers as soapy, bitter, metallic,earthy or dirty, and astringent. Soapy is typically characterized by thepresence of dodecanal or dodecanol. Bitter taste may occur in thepresence of alkyl amines or alcohols.

Extraction Mixture

In one step of the process herein, the water-soluble surfactantcomposition is contacted with an extraction solvent and water to form anextraction mixture comprising an aqueous phase and a solvent phase. Inone embodiment, such as in a laboratory-scale batch process, theextraction mixture is then mixed vigorously for a period of from about10 seconds to one minute. After mixing, the extraction mixture isallowed to rest for a period of from about 15 minutes to about 2 hours.Where multiple extractions are conducted in succession, the separationtime may be shortened to a period of from about 10 to about 20 minutes.

In another embodiment, such as on an industrial scale, an industrialcentrifuge extractor such as the BXP 190 manufactured by RousseletRobatel may be used to take advantage of the density differences betweentwo fluids to separate them via centrifugation. The devices can beoperated in a countercurrent setup or as single stage extractions.Successive continuous extractions using an industrial centrifugeextractor can occur quite quickly, even in a matter of seconds, to reachthe desired treated surfactant material.

The extraction mixture then contains the extraction solvent, surfactantand undesirable non-polar materials. In one embodiment, the extractionmixture comprises from about 10% to about 90%, by weight of the mixture,of water; from about 5% to about 60%, by weight of the mixture, ofwater-soluble surfactant; less than 5%, by weight of the mixture, ofundesirable non-polar materials; and from about 10% to about 90%, byweight of the mixture, of solvent. In one embodiment, the ratio ofextraction solvent to water-soluble surfactant in the extraction mixtureis from about 1:10 to about 10:1, alternatively is from about 1:2 toabout 2:1.

The water included in the extraction mixture may be provided in thewater-soluble surfactant composition itself when obtained as an aqueoussolution from the commercial supplier and/or may be water that is addedduring the extraction process. In some instances, the water level in awater-soluble surfactant aqueous solution may be reduced beforecontacting the water-soluble surfactant composition with the extractionsolvent to reduce the level of solvent needed for the processes herein.

In one embodiment, the extraction mixture further comprises a phaseseparation enhancer selected from salts, pH modifiers, and mixturesthereof.

In one embodiment, after the extraction mixture is formed and containsboth an aqueous phase and a solvent phase, the aqueous phase is thenseparated from the solvent phase. In another embodiment, after the twophases are separated, the extraction solvent is recovered from thesolvent phase and reused in subsequent liquid-liquid extractionprocesses.

In one embodiment, during the step of separating the aqueous phase fromthe solvent, the temperature is adjusted to improve the extractionefficiency. As used herein, “extraction efficiency” refers to theability of the process to remove undesirable impurities from thewater-soluble surfactant composition in need of treatment.

In one embodiment, during the process, the pressure under which theprocess takes place is adjusted to improve the extraction efficiency.

In one embodiment, the process steps herein are repeated in successionuntil the desired amount of undesirable non-polar impurities is removed.In one embodiment, the treated water-soluble surfactant composition iscollected and the process steps are repeated at least two times,alternatively at least 3 times, still alternatively at least 4 times insuccession, each time further reducing the level of undesirablewater-soluble impurities.

In another embodiment, multiple extractions are performed in seriesafter removal of the extraction solvent from preceding extraction.

As used herein, the terms “extract” and “extraction” refer to theprocess of removing undesirable components from the desirable componentsof the water-soluble surfactant composition. The undesirable componentscould be associated with microorganism removal and/or other impurity orcontaminant removal, primarily via preferential solubility in theextraction solvent.

As used herein, the terms “removal”, “reduce”, “reduction”, and theirderivatives refer to partial reduction of the number or concentration ofundesirable materials and may be considered in a relative sense,particularly when multiple repetitions of the process steps herein areused in succession on the same starting material.

Extraction Solvent

As used herein, “extraction solvent” refers to any liquid orsupercritical fluid that can be used to solubilize undesirable non-polarmaterials that are contained within a water-soluble surfactantcomposition. Organic solvents with acceptable safety profiles that willform a liquid bilayer with aqueous surfactants could be used eitheralone or in combination with other solvents such as ethyl acetate,ethanol, propylene glycol, PEGs, other ethers or esters, or othersolvents, etc. to achieve a similar result. One example of a usefulsupercritical fluid is carbon dioxide. A range of ratios of solvent tosurfactant, a range of surfactant concentrations, the mixing and/orextraction conditions, etc. are variables that could be optimized for aparticular application of this general approach.

Without being limited by theory, when thorough chemical composition dataon the undesirable non-polar materials found in the water-solublesurfactant composition in need of treatment are obtained throughin-depth chemical characterization and are well-understood, aninvestigation can be initiated to determine if the impurities areprimarily responsible for malodors and off-tastes, or if the surfactantsthemselves are contributing a large fraction of the malodors and offtastes.

Extraction solvents useful herein include those having individual Hansensolubility parameters of a dispersion force component (δ_(D)) rangingfrom about 15 to about 17 (MPa)^(0.5), a polar component (δ_(P)) rangingfrom 0 to about 9 (MPa)^(0.5) and a hydrogen bonding component (δ_(H))ranging from 0 to about 11 (MPa)^(0.5).

In one embodiment, the solvent has individual Hansen solubilityparameters of a dispersion force component (δ_(D)) ranging from about 13to about 19 (MPa)^(0.5), a polar component (δ_(P)) ranging from about 2to about 9 (MPa)^(0.5) and a hydrogen bonding component (δ_(H)) rangingfrom about 2 to about 11 (MPa)^(0.5). In one embodiment, the polarcomponent ranges from about 4 to about 6, in another embodiment, thehydrogen bonding component ranges from about 6 to about 9.

In addition to Hansen solubility parameters, the solvent will formdistinct layers when combined with water and the water-solublesurfactant composition. In order to quickly determine whether a solventwill meet this criteria, the following visual separation test may beused: using a 30 ml glass vial, add 10 mL of the proposed extractionsolvent, 10 mL of a 30% aqueous solution of the water-soluble surfactantcomposition, cap the vial, shake vigorously for 30 seconds, allow torest for 30 minutes, visually inspect for visible precipitation and twodistinct aqueous layers. If there is no visible precipitation and atleast two distinct layers are formed, the solvent passes the visualseparation test and may be used as an extraction solvent according tothe processes set forth herein.

In one embodiment, the extraction solvents useful herein have a logPvalue of greater than 0.5.

Extraction solvents useful herein include ethyl acetate, water-saturatedethyl acetate, ethyl propionate, ethyl butyrate, ethyl pentanoate, ethylcaproate, ethyl caprylate, ethyl pelargonate methyl acetate, methylpropionate, methyl butyrate, short chain esters and mixtures thereof. Inone embodiment, the extraction solvent is selected from food grade ethylesters.

In one embodiment, the extraction solvent is substantially free of (i.e.comprises no reasonably measurable quantity of) ethyl lactate,alternatively contains less than 0.0001% of ethyl lactate.

Other extraction solvents useful herein include ketones such as methylethyl ketone, ethers such as di-n-propyl ether, lactones, acetals, andmixtures thereof.

Other extraction solvents useful herein include those selected fromhexane, cyclohexane, heptane, chloroform, toluene, methylene chloride,methyl nonafluoroether, ethyl nonafluoroether, carbon tetrachloride, andmixtures thereof. HFE 7100, HFE 7200, and HFE 7500 are tradenames ofcommercially available hydrofluoroethers available from TCI AMERICA,9211 N. Harborgate Street, Portland, Oreg. 97203, U.S.A.

Mixtures of extraction solvents may also be used.

In one embodiment, the extraction mixture is substantially free of (i.e.comprises no reasonably measurable quantity of) THF.

In one embodiment, the extraction mixture comprises mono alkyl phosphateand is substantially free of (i.e. comprises no reasonably measurablequantity of) 1-octanol and phenoxy ethanol.

Extraction solvents useful herein also include supercritical fluids suchas carbon dioxide. As used herein, “supercritical carbon dioxide” iscarbon dioxide that is at a temperature and a pressure greater than Tr=1and Pr=1. Tr is T/Tc where T is the present temperature of thesupercritical carbon dioxide and Tc is the critical temperature. Pr isP/Pc where P is the present pressure of the supercritical carbon dioxideand Pc is the critical pressure. Tc, the critical temperature for carbondioxide (CO2), is 31.1 degrees Celsius (deg. C.), or 304.1 degreesKelvin (K), and Pc is 73 atmospheres (atm) or about 1073 pounds persquare inch (PSI).

In more general terms, supercritical carbon dioxide refers to carbondioxide that is in a fluid state while also being at or above both itscritical temperature and pressure. Carbon dioxide usually behaves as agas in air at standard temperature and pressure (STP) or as a solidcalled dry ice when frozen. If the temperature and pressure are bothincreased from standard temperature and pressure to be at or above thecritical point for carbon dioxide, it can adopt properties midwaybetween a gas and a liquid. More specifically, it behaves as asupercritical fluid above its critical temperature (31.1 deg. C.) andcritical pressure (73 atm), expanding to fill its container like a gasbut with a density like that of a liquid. The supercritical fluid regionof the phase diagram is defined as a temperature above the criticaltemperature (31.1 deg. C.) to a pressure above the critical pressure(73.8 bar or 1070 PSI).

When using a supercritical fluid as the extraction solvent, it ispossible to choose a “batch-type” system or choose a “continuous-type”system. The batch systems can be used in parallel or in series, operatedon a cyclic basis (at prescribed residence times), be sequentiallyloaded, processed, and unloaded, and yield a sufficient bulk removalefficiency. The “continuous-type”systems generally refer to a number ofbatch vessels, operated sequentially, with the supercritical carbondioxide gas flow and the sequential loading, processing, and unloadingof the feed and product solids can be envisioned as counter current flowof the solids movement from feed to product with respect to the flow ofthe supercritical carbon dioxide. The directional loading, processing,and unloading is opposite to the flow of the supercritical carbondioxide. This type of “continuous”, counter current operation isgenerally referred to as continuous, counter current, sequencing-batchoperation. Therefore, when there are one or two batch stages, in seriesor parallel, the term “batch” tends to be used, and when there are threeor more stages, if they operate in parallel flow to the supercriticalcarbon dioxide, the term “batch” is also used. However, when theyoperate in counter current flow of the material to be extracted to thesupercritical carbon dioxide, we call them counter current“sequencing-batch” simulating counter current flows of material feed anddesired product to the flow direction of the supercritical carbondioxide. It should be understood that “continuous” can also define aprocess in which the feed and solvent are fed continuously through afixed system and the products are continuously removed.

When the supercritical fluid is selected as the extraction solvent, theseparation of the aqueous phase from the solvent phase may occur byreleasing the temperature and pressure placed upon the supercriticalfluid, allowing the fluid to return to a gaseous state.

Selection of an Extraction Solvent

In one embodiment, the process further comprises a step of selecting anextraction solvent suitable for use with the water-soluble surfactant inneed of treatment.

Such step includes evaluating the extraction solvent under considerationwith the water-soluble surfactant in need of treatment. Evaluation ofthe solvent includes combining the proposed solvent with thewater-soluble surfactant composition in need of treatment to determinewhether the solvent forms a 2-phase system with the surfactant watermixture. The pH, temperature, or ionic strength may be adjusted todeliver a good two-phase break, and also to optimize the extractionefficiency. The extraction solvent should not cause significantprecipitation when combined with the water/surfactant mixture. Since asuccessful two-phase separation will be achieved with suitableextraction solvents, the solvent polarity is expected to preferentiallyextract non-polar impurities into the extraction solvent layer and awayfrom the aqueous surfactant phase. In one embodiment, the solvent willbe food grade and easily separable from the aqueous/surfactant phase.Selection of a solvent that is easily recoverable from the extractedimpurities is also desirable, i.e. by fractional distillation, so thatit can be re-used for subsequent extractions.

The solvents selected for the solubilization method of this inventionare based upon solubility parameters and cohesion properties explainedby Charles Hansen in “Hansen Solubility Parameters: A User's Handbook”by Charles M. Hansen, CRC Press (2007) and in “The CRC Handbook andSolubility Parameters and Cohesion Parameters,” Edited by Allan F. M.Barton (1999). Each material is defined by three points in 3D space andthese three points are known as the Hansen Solubility Parameters (HSP)which may be defined as follows.

Solubility parameters are theoretically calculated numerical constantswhich are a useful tool in predicting the ability of a solvent materialto dissolve a particular solute. When the solubility parameters of asolvent falls within the solubility parameter range of a solute, i.e.,the material to be dissolved, solubilization of the solute is likely tooccur. There are three Hansen empirically- and theoretically-derivedsolubility parameters, a dispersion-force component (δ_(D)), a polar ordipole interaction component (δ_(P)) and a hydrogen-bonding component(δ_(H)). Each of the three parameters (i.e., dispersion, polar andhydrogen bonding) represents a different characteristic of solvency, orsolvent capability. In combination, the three parameters are a measureof the overall strength and selectivity of a solvent. The Total Hansensolubility parameter, which is the square root of the sum of the squaresof the three parameters mentioned previously, provides a more generaldescription of the solvency of the solvents. Individual and totalSolubility Parameter units are given in MPa^(0.5) or (J/cc)^(0.5).

These three parameters can be treated as co-ordinates for a point inthree dimensions also known as the Hansen space. The nearer twomolecules are in this three dimensional space, the more likely they areto dissolve into each other. To determine if the parameters of twomolecules (usually a solvent and a polymer) are within range a valuecalled interaction radius (R₀) is given to the substance beingdissolved. This value determines the radius of the sphere in Hansenspace and its center is the three Hansen parameters. To calculate thedistance (Ra) between Hansen parameters in Hansen space the followingformula is used.

(Ra)²=4(δ_(d2)−δ_(d1))²+(δ_(p2)−δ_(p1))²+(δ_(h2)−δ_(h1))²

The Hansen solubility parameters can be calculated by “MolecularModeling Pro” software, version 5.1.9 (ChemSW, Fairfield Calif.,www.chemsw.com) or Hansen Solubility from Dynacomp Software. Thesolubility parameters of solvents useful herein are shown in Table 1,below.

TABLE 1 Disper- Polar- Hydrogen Ra (With Ra (With sion ity Bonding EthylDodeca- Component (δD) (δP) (δH) Acetate) nol) ethyl acetate 15.8 5.37.2 0 4.5 Carbon Dioxide 15.7 6.3 5.7 1.8 5.7 hexane 14.9 0 0 9.1 10.0heptanes 15.3 0 0 9 10.2 benzene 18.4 0 2 9.1 11.8 diethyl ether 14.52.9 5.1 4.1 4.3 di-n-propyl ether 15.5 2.3 4.5 4.1 5.7 methylene 18.26.3 6.1 5 9.4 chloride carbon 17.8 0 0.6 9.4 12.0 tetrachloridepropylene 20 18 4.1 15.5 19.6 Carbonate propylene glycol 15.6 5.6 9.82.6 3.9 methyl ether acetate 1,1,1- 16.8 4.3 2 5.7 9.2 trichloroethanemethyl 13.74 3.59 4.14 5.4 5.2 nonafluorobutyl ether* ethyl 14.31 4.363.98 4.5 5.5 nonafluorobutyl ether* *Methyl and Ethyl NonafluorobutylEthers are commercially available from TCI AMERICA, 9211 N. HarborgateStreet, Portland, OR 97203, U.S.A.

Aqueous Phase

As used herein, “aqueous phase” refers to the portion of the extractionmixture containing water, water-soluble surfactant, and otherwater-soluble materials.

In one embodiment, the processes of the present invention may furtherinclude a step of adjusting the ionic strength of the aqueous phase upor down to improve the extraction efficiency.

Solvent Phase

As used herein, “solvent phase” refers to the portion of the extractionmixture containing the extraction solvent, the undesirable non-polarmaterials, and other water-insoluble materials.

Generally, the solvent phase and the aqueous phase will be immiscible.

In one embodiment, after separation of the aqueous and solvent phases,the aqueous phase still contains small amounts of the extraction solventand the extraction solvent may be further removed from the aqueous phaseby subsequent extraction steps, evaporation (such as with a rotavapor oropen-air, optionally with a nitrogen stream) or combinations thereof.

Separating the Aqueous Phase from the Solvent Phase

As discussed more fully above, the separation of the aqueous phase fromthe solvent phase may occur using traditional liquid-liquid extractiontechniques. Such separation may be crudely done based upon the phasebreak, particularly where multiple rounds of extraction are planned. Ona lab bench or pilot plant scale this may mean by use of a separatoryfunnel, while on an industrial scale, this may mean by use of standardequipment for centrifugation and separation in a continuous process orin very large tanks equipped for separation on a batch basis.

In one embodiment, the step of separating the aqueous phase from thesolvent phase further comprises centrifuging the extraction mixture.

In one embodiment, the extraction mixture is mixed for from about 10seconds to about one minute with vigorous mixing and at ambienttemperature before allowing the mixture to settle into two phases andseparating the aqueous phase from the solvent phase.

In one embodiment, the step of separating the aqueous phase from thesolvent phase comprises reducing the heat and pressure applied to asupercritical fluid, such as carbon dioxide, allowing the supercriticalfluid to return to a gaseous state, and allowing the gas to escape fromthe extraction mixture.

The process may further comprise the step of removing any residualsolvent from the aqueous phase. In one embodiment the step of removingany residual solvent from the aqueous phase includes the use of anindustrial method selected from vacuum stripping (with or without heat),fractional distillation, wiped-film evaporation, carbon filtration, orcombinations thereof.

Recovering the Treated Water-Soluble Surfactant

The processes according to the present invention may further include astep of recovering the treated water-soluble surfactant composition fromthe aqueous phase by evaporation or other traditional means.

In one embodiment, the treated water-soluble surfactant compositioncontains from about 10% to about 50%, alternatively from about 20% toabout 30% of the treated water-soluble surfactant, from about 60 toabout 90%, alternatively from about 70% to about 80% water, and 1% orless, alternatively 0.7% or less, alternatively 0.5% or less,alternatively 0.1% or less, alternatively 0.05% or less, alternatively0.01% or less, of undesirable non-polar materials, all by weight of thetreated composition.

In one embodiment, the treated mono alkyl phosphate surfactantcomposition contains 0.7% or less, alternatively 0.5% or less,alternatively 0.1% or less, alternatively 0.05% or less, alternatively0.01% or less, by weight of the treated composition, of undesirablenon-polar materials.

In one embodiment, the treated cocoamidopropyl betaine surfactantcomposition contains 0.1% or less, alternatively 0.07% or less,alternatively 0.05% or less, alternatively 0.01% or less, alternatively0.005% or less, 0.0001% or less, alternatively no measurable quantity,by weight of the treated composition, of amine and amide materials.

In one embodiment, the treated cocoamidopropyl betaine surfactantcomposition contains at least 20% cocoamidopropyl betaine surfactant and10 ppm or less, alternatively 5 ppm or less, alternatively 1 ppm orless, alternatively 500 ppb or less, alternatively no measurablequantity, by weight of the treated composition, of amine and amidematerials.

In one embodiment, the treated cocoamidopropyl betaine surfactantcomposition contains 0.1% or less, alternatively 0.07% or less,alternatively 0.05% or less, alternatively 0.01% or less, alternatively0.005% or less, 0.0001% or less, alternatively no measurable quantity,by weight of the treated composition, of undesirable non-polarmaterials.

In one embodiment, the treated water-soluble surfactant compositioncontains from about 10% to about 50%, alternatively from about 20% toabout 30% of the treated water-soluble surfactant, from about 60 toabout 90%, alternatively from about 70% to about 80% water, and 1% orless of total alcohols, all by weight of the treated composition.

In one embodiment, the treated mono alkyl phosphate surfactantcomposition contains 0.7% or less, alternatively 0.5% or less,alternatively 0.1% or less, alternatively 0.05% or less, alternatively0.01% or less, by weight of the treated composition, of total alcohols.

Recycling the Solvent

In one embodiment, the process further includes a step of separating theextraction solvent from the solvent phase and optionally reusing theextraction solvent for further liquid-liquid extraction processes.

In one embodiment, the step of recycling the solvent includes the use ofa fractionating column (or distillation tower). Fractionating columnshave been shown capable of separating these types of streams andremoving them for varying uses. An example process that incorporates afractionating column step is shown in FIG. 1. Design of thefractionating column will need to take into account the potentialmarkets for the varying fractions, throughput needs for the system, andoverall costs. The size and number of plates used in the distillationtower may be selected with these factors in mind.

A fractionating column or fractionation column may be used in thedistillation of liquid mixtures so as to separate the mixture into itscomponent parts, or fractions, based on the differences in theirvolatilities. Fractionating columns may vary in size and are used insmall scale laboratory distillations as well as for large-scaleindustrial distillations.

Fractionating columns help to separate the mixture by allowing the mixedvapors to cool, condense, and vaporize again in accordance with Raoult'slaw. With each condensation-vaporization cycle, the vapors are enrichedin a certain component.

In a typical fractional distillation, a liquid mixture is heated in thedistilling flask, and the resulting vapor rises up the fractionatingcolumn. The vapor condenses on glass spurs (known as trays or plates)inside the column, and returns to the distilling flask, refluxing therising distillate vapor. The hottest tray is at the bottom of the columnand the coolest tray is at the top. At steady-state conditions, thevapor and liquid on each tray reach an equilibrium. Only the mostvolatile of the vapors stays in gas form all the way to the top, whereit may then proceed through a condenser, which cools the vapor until itcondenses into a liquid distillate. The separation may be enhanced bythe addition of more trays (to a practical limitation of heat, flow,etc.).

Fractional distillation is one of the unit operations of chemicalengineering. Fractionating columns are widely used in the chemicalprocess industries where large quantities of liquids have to bedistilled. Many fractions can be recovered through this method and forindustrial processes, the limitation is typically only productrequirements and economics.

Industrial distillation is typically performed in large, verticalcylindrical columns known as “distillation towers” or “distillationcolumns” with diameters ranging from about 65 centimeters to 6 metersand heights ranging from about 6 meters to 60 meters or more. Industrialdistillation towers are usually operated at a continuous steady state.Unless disturbed by changes in feed, heat, ambient temperature, orcondensing, the amount of feed being added normally equals the amount ofproduct being removed.

Other means of recycling the solvent phase include use of a cycloneseparator. It may be possible to use the density differences of thematerials in the solvent phase to drive their separation. This approachhas the advantage of typically being more economical to install andoperate, but may reduce the degree of separation that can be achievedversus a distillation approach.

Preparing a Solid Water-Soluble Surfactant

In one embodiment, the process further comprises the step of heating asolid impure surfactant material to its melting point. In oneembodiment, heating the solid impure surfactant material to atemperature of from about 25° C. to about 80° C., alternatively fromabout 30° C. to about 60° C. before the step of contacting with anextraction solvent and water.

Incorporating into Oral Care Compositions

The processes of the present invention may further include a step ofincorporating the treated water-soluble surfactant composition into anoral care composition.

Oral Care Compositions

The treated water-soluble surfactant compositions resulting from theprocesses according to the present invention, may, in one embodiment, beincorporated into an oral care composition having improved taste vs. awater-soluble surfactant untreated by the processes set forth herein.

As used herein, “oral care composition” is meant a product, which in theordinary course of usage, is not intentionally swallowed for purposes ofsystemic administration of particular therapeutic agents, but rather isretained in the oral cavity for a time sufficient to contactsubstantially all of the dental surfaces and/or oral tissues forpurposes of oral activity. The oral care composition may be in variousforms including toothpaste, dentifrice, tooth gel, subgingival gel,mouthrinse, mousse, foam, mouthspray, lozenge, chewable tablet, chewinggum or denture product. The oral care composition may also beincorporated onto strips or films for direct application or attachmentto oral surfaces.

Procedure for Assessing Extraction Efficacy

In one embodiment, in conjunction with the processes according to thepresent invention, a step of assessing extraction efficacy is performedon the water-soluble surfactant composition. Such as step may beperformed as follows:

1. Supply a water-soluble surfactant composition.

2. To the water-soluble surfactant composition, add the extractionsolvent, such as ethyl acetate, all in a separatory funnel.

3. Mix vigorously by shaking the separatory funnel for approximately 1minute and then allow the liquid layers to separate.

4. Collect the aqueous layer containing the desirable water-solublesurfactant.

5. Separately collect the solvent layer containing the undesirablematerials and either discard or utilize the solvent and undesirablematerials for other purposes. For example, if the undesirable materialsare starting materials in the water-soluble surfactant manufacture, theycould be isolated and re-used to make more surfactant. The extractionsolvent could be purified for later re-use in the extraction procedure.

6. Analyze samples from both the pre- and post-extracted oral carecomponent via immersion Solid Phase Microextraction (SPME) (or LLE)followed by GC-MS (using an Agilent model 6890 GC & model 5973 MassSpectrometric Detector, Agilent Technologies, Wilmington, Del., USA).Compare the impurity levels in the pre- and post-extracted samples todetermine the efficiency of their removal.

7. Smell and/or taste the pre- and post-extracted material directly orafter spiking into an Oral Care product to sensorially dimension thelevel of improvement.

EXAMPLES Example I Improved MAP L213/S Surfactant

Undesirable non-polar materials were extracted from MAP L213/S (a monoalkyl phosphate surfactant in aqueous solution, see Table 1 above),supplied by Rhodia, using the processes set forth herein wherein ethylacetate (supplied by Honeywell Burdick & Jackson, Muskegon, Mich., USA)was used as the extraction solvent. The extracted materials were thenanalyzed and the treated MAP L213/S was evaluated for taste and odorafter the extraction and shown to be very mild, especially when comparedwith the starting MAP L213/S material. The undesirable materials removedfrom the ML213/S commercially supplied material are set forth in Table3, below. The following process steps were taken:

1. 100 grams of MAP L213/S were placed into a clean 250 mL separatoryfunnel.2. 100 mL of ethyl acetate was added to the separatory funnel, which wasstoppered, and shaken vigorously for approximately 1 minute.3. The separatory funnel contents were then rested for a period of timeuntil they settled into two visibly distinct layers.4. The bottom layer (treated MAP L213/S) was drained from the separatoryfunnel into a second, clean 250 mL separatory funnel.5. The ethyl acetate was separately collected and set aside for otherpurposes.6. A second aliquot of 100 mL of fresh ethyl acetate was then added tothe treated MAP L213/S in the separatory funnel and the steps 2-5 wererepeated for a total of 5 times.7. After the last extraction step, the aqueous layer was collected intoa round bottom flask, which was then placed on a rotavapor (model RE111supplied by BUCHI Labortechnik AG in Flawil, Switzerland). The waterbath of the rotavapor was set at 80° C. and allowed to run until theethyl acetate odor is no longer perceived.7. The mass of the treated MAP L213/S surfactant was then obtained andwater was added to make up for any mass loss due to water loss alongwith the EtOAc removal.

TABLE 3 Results of Mono alkyl phosphate LLE treatment with EtOAc ControlReten- (Pre- Post tion extract) Extract Area Time Peak Peak Reduc-Undesirable Material (Min) Area Area tion (%) Undecane 3.39 1216114 0100.0 Dodecene Isomer 4.35 3218343 0 100.0 Dodecene Isomer 4.42 34506180 100.0 Dodecene Isomer 4.46 2311369 0 100.0 Dodecene Isomer 4.574329376 0 100.0 Dodecene Isomer 4.66 2547216 0 100.0 Tridecene Isomer5.09 2406145 0 100.0 Tridecene Isomer 5.15 1220445 0 100.0 TrideceneIsomer 5.19 438095 0 100.0 Tridecene Isomer 5.29 1367495 0 100.0Tridecene Isomer 5.38 1114436 0 100.0 Tetradecene Isomer 5.45 674727 0100.0 Tetradecene Isomer 5.52 1030783 0 100.0 Tetradecene Isomer 5.591218184 0 100.0 Tetradecene Isomer 5.63 1589820 0 100.0 TetradeceneIsomer 5.77 573418 0 100.0 Tetradecene Isomer 5.80 220422 0 100.0Tetradecene Isomer 5.83 184627 0 100.0 Tetradecene Isomer 5.88 300141 0100.0 Tetradecene Isomer 5.97 199647 0 100.0 Tetradecene Isomer 5.99175759 0 100.0 Tetradecene Isomer 6.06 177721 0 100.0 Pentadecane 6.22669888 0 100.0 Methyl 4,6-decadienyl 6.61 1023628 0 100.0 etherHexadecane 6.83 1645290 0 100.0 Dodecanal 7.57 2654710 129439 95.1Unknown 7.60 776038 0 100.0 Unknown 7.64 1108611 0 100.0 Unknown 7.701879031 0 100.0 Methyl 6,8-dodecadienyl 7.80 1223734 0 100.0 etherUnknown 7.84 1463962 0 100.0 Unknown 7.95 3115904 0 100.0Butyl-substituted 8.04 5371992 0 100.0 tetrahydrofuran Branched alcohol8.29 1323195 0 100.0 Branched alcohols 8.38 4633193 0 100.0 Branchedalcohols 8.48 8500950 0 100.0 Dodecanol 8.88 101956289 932638 99.1Ethylene glycol 10.23 55816598 522217 99.1 mondodecyl ether Diethyleneglycol 12.00 31588284 560933 98.2 monododecyl ether Triethylene glycol14.90 8518697 264967 96.9 monododecyl ether Average % 99.7 Reduction

The resulting treated MAP L213/S was then subjected to comparative tastetesting as follows:

The following MAP L213/S compounds (all based upon the MAP L213/Ssurfactant commercially available from Rhodia) were subjected to a 6person panel for tasting. Each MAP material was diluted to a level of 1%surfactant in distilled water and neutralized to pH 7. 10 mL sampleswere provided in 15 mL cups to the panelists. Panelists were instructedto not sample materials more often than once in the morning and once inthe afternoon in order to provide enough time for the palate to clearbetween samples and were instructed to not eat or drink within 15minutes before sampling. The panelist was instructed to empty thecontents of the cup into their mouth without swallowing, swish theproduct for 10-20 seconds, expectorate, wait 10-20 seconds, and thenrate their perceptions for the following categories on a scale of 0 to60:1) soapy taste; 2) bitterness amount; 3) other off-taste amount; 4)“soapy taste” intensity; 5) “bitter taste” intensity.

176=Rhodia L213/S, lot SW10G-4636 251=Rhodia L213/S, lot 012

389=Rhodia L213/S, lot 010

462=Rhodia L213/S, lot 011

937=Rhodia L213/S, lot 001 extracted with ethyl acetate pursuant to theprocess steps set forth above in this Example I

Control=Rhodia L213/S, lot 001

As may be seen in Table 4, the control and the comparative examples 176,251, 389, and 462, all had significantly higher ratings for negativetaste elements such as the soapy taste, bitterness amount, otheroff-taste amount, soapy taste intensity, and bitter taste intensity thanthe MAP composition treated with ethyl acetate according to theprocesses set forth herein.

TABLE 4 Attribute n = 6 176 251 389 462 937 CTL (Comp) (Comp) (Comp)(Comp) (Example I) Soapy 41.25 47.50 33.75 30.42 38.75 12.50 TasteBitterness 32.50 44.08 42.08 39.58 44.58 5.83 Amount Other 32.50 34.0024.58 26.25 26.08 3.75 Off-taste Amount “Soapy 42.08 45.00 32.00 28.7539.25 7.50 Taste” Intensity “Bitter 31.25 39.17 41.25 38.75 42.92 3.17Taste” Intensity

Example II Improved Cocoamidopropyl Betaine Surfactant

Undesirable non-polar materials were extracted from cocoamidopropylbetaine surfactant, supplied by Stepan, Mexico SA DE CV (Matamoros, MX),using the process steps shown in Example I, except that 20 gramscocoamidopropyl betaine and 20 mL of solvent were used (in place of 100grams of MAP and 100 mL of solvent) and only 3 repetitions (stages) ofsteps 2 through 5—substituting the cocoamidopropyl betaine for the MAPL213/S. The extracted materials were then analyzed and the treatedcocoamidopropyl betaine surfactant was evaluated for taste and odorafter the extraction and shown to be very mild, especially when comparedwith the starting material. The undesirable materials removed from thecommercially supplied material are set forth in Table 5, below.

TABLE 5 Cocoamidopropyl Betaine - Pre and Post 3 Stages of EtOAcExtraction Control Reten- (Pre- Post tion extract) Extract Area TimePeak Peak Reduc- Impurity (Min) Area Area tion (%) — — — — — Cyclohexylbenzene 7.43 421510 0 100.0 Dodecanal 7.57 2718310 91634 96.6 Methyldodecanoate 8.04 3597403 12025 99.7 Benzyl alcohol 8.52 11186150 37037196.7 Tetradecanal 8.70 396280 0 100.0 Dodecanol 8.87 1590140 319173 79.9Methyl tetradecanoate 9.11 515756 0 100.0 Biphenyl 9.19 2524375 0 100.0Diphenyl ether 9.28 8312954 0 100.0 Tetradecanol 9.86 264984 0 100.0Unknown 10.16 1794756 570477 68.2 N,N- 10.85 737881 0 100.0Dimethyldodecanamide Benzoic Acid 11.13 627445 70858 88.7 Dodecanoicacid 11.23 7295585 295959 95.9 N,N- 11.83 300264 0 100.0Dimethylpalmitamide Tetradecanoic acid 12.26 2070533 93129 95.5Dodecanamide 12.80 378693 0 100.0 Unknown 13.66 948057 515784 45.6Tertiary alkyl 14.26 1761483 495040 71.9 dimethylamine Average % 91.5Reduction

Example III Improved Lauryl Betaine Surfactant

Undesirable non-polar materials were extracted from lauryl betainesurfactant, supplied by Mason Chemical Company (Arlington Heights, Ill.,USA), using the process steps shown in Example I, substituting thelauryl betaine for the MAP L213/S and only four repetitions of steps(stages) 2 through 5 were completed. The extracted materials were thenanalyzed and the treated lauryl betaine surfactant was evaluated fortaste and odor after the extraction and shown to be very mild,especially when compared with the starting material. The undesirablematerials removed from the commercially supplied material are set forthin Table 6, below.

TABLE 6 Lauryl Betaine - Pre and Post 4 Stages of EtOAc ExtractionControl Reten- (Pre- Post tion extract) Extract Area Time Peak PeakReduc- Impurity (Min) Area Area tion (%) Dodecene Isomer 4.14 268607 0100.0 Dodecene Isomer 4.25 269099 0 100.0 Dodecene Isomer 4.36 100143 0100.0 Dodecene Isomer 4.42 249301 0 100.0 Dodecene Isomer 4.51 210691 0100.0 Dodecene Isomer 4.61 533604 0 100.0 Dodecene Isomer 4.68 77816 0100.0 Tertiary Alkyl Dimethyl 5.83 119401 0 100.0 amine Tertiary AlkylDimethyl 6.11 110815 0 100.0 amine 2-Ethyl-1-hexanol 6.18 197861 0 100.0N,N-Dimethyl-1- 7.05 12603358 1716473 86.4 dodecanamine Average % 98.8Reduction

Example IV Improved Sodium Lauryl Sulfate Surfactant

Undesirable non-polar materials were extracted from sodium laurylsulfate surfactant, supplied by Stepan (Winder, Ga., USA), using theprocess steps shown in Example I, substituting the sodium lauryl sulfatefor the MAP L213/S and only three repetitions (stages) of steps 2through 5 were completed. The extracted materials were then analyzed andthe treated sodium lauryl sulfate surfactant was evaluated for taste andodor after the extraction and shown to be very mild, especially whencompared with the starting material. The undesirable materials removedfrom the commercially supplied material are set forth in Table 7, below.

TABLE 7 SODIUM LAURYL SULFATE - Pre and Post 3 Stages of EtOAcExtraction Control Reten- (Pre- Post tion extract) Extract Area TimePeak Peak Reduc- Impurity (Min) Area Area tion (%) — — — — — Undecane3.39 1139583 0 100.0 Dodecane 4.16 17065669 1858091 89.1 Dodecene isomer4.39 9997068 770380 92.3 Dodecene isomer 4.45 5165264 370370 92.8Dodecene isomer 4.49 1864387 224856 87.9 Dodecene isomer 4.60 6606623518956 92.1 Dodecene isomer 4.69 4871544 384054 92.1 Tridecane 4.89434688 91475 79.0 Tetradecane 5.58 6864662 841425 87.7 Tetradeceneisomer 5.78 1799963 134020 92.6 Tetradecene isomer 5.84 580558 5029991.3 Tetradecene isomer 5.88 235342 34614 85.3 Tetradecene isomer 5.97729601 44650 93.9 Tetradecene isomer 6.06 559398 209913 62.5 Pentadecane6.23 151876 28738 81.1 Methyl 4,6-decadienyl 6.61 2127943 169814 92.0ether Hexadecane 6.84 1055440 307915 70.8 1-Chlorododecane 7.31 932377120438 87.1 Alkyl Benzene 7.72 646264 42187 93.5 Alkyl Benzene 7.79732825 62895 91.4 Alkyl Benzene 7.95 825458 70947 91.4 Alkyl Benzene8.22 158968 19055 88.0 Alkyl Benzene 8.28 857712 82212 90.4 AlkylBenzene 8.34 313335 14071 95.5 Alkyl Benzene 9.35 120877 0 100.0Dodecanol 8.87 20170340 8855647 56.1 Tetradecanol 9.85 5956311 288544151.6 Hexadecanol 10.77 515519 352413 31.6 Average % 84.3 Reduction

Example V Dentifrice Compositions

Dentifrice compositions according to the present invention are shownbelow as Examples Va-Vi in Table 8. These compositions containsurfactants resulting from the process set forth herein in ExamplesI-IV. Such compositions have improved taste versus compositionscontaining the untreated commercially available water-solublesurfactants.

TABLE 8 Dentifrice Examples Ingredient Va Vb Vc Vd Ve Vf Vg Vh ViCarbomer 956 0.2 0.3 0.2 0.2 0.2 0.2 0.2 CMC 0.75 0.2 1.0 1.0 1.0 1.0Color Solution (1%) 0.05 0.05 0.50 0.75 0.18 0.02 0.25 0.05 0.05Wintergreen Spice 0.15 Flavor Fruit Mint Flavor 0.55 Mint Flavor 0.590.45 0.42 1.0 1.2 1.0 1.0 Cinnamon Flavor 0.5 WS-23 0.02 0.05 0.02 WS-30.02 0.05 0.02 MGA 0.2 Menthol 0.52 0.55 0.56 0.15 0.58 G-180 0.01 0.030.015 0.004 0.01 0.01 0.03 0.008 0.02 Potassium Sorbate 0.004 0.0080.004 0.004 Poloxamer 407 1.0 0.2 0.2 0.2 0.2 0.2 Polyethylene Glycol3.0 3.0 3.00 300 Polyethylene Glycol 2.3 600 Propylene Glycol 10.0Sweetener 0.46 0.5 0.45 0.4 0.58 0.4 0.4 0.4 0.4 Silica Abrasive 22.031.0 20.0 21.0 17.0 15.0 15.0 15.0 15.0 Sodium Benzoate 0.004 0.0040.004 0.004 Silica Thickening 2.0 7.0 7.0 7.0 7.0 Sodium Bicarbonate1.50 9.0 Sodium Carbonate 0.50 NaOH 50% Soln 1.74 2.20 2.0 2.0 2.0 2.0Na Lauryl Sulfate 4.0 5.0 3.0 4.0 4.0 3.0 2.0 according to Example IVSodium Fluoride 0.243 0.243 0.243 Sodium MFP 0.76 0.76 0.76 0.76 0.760.76 Glycerin USP 9.0 11.9 33.0 9.0 99.7% Sorbitol Soln USP 24.3 24.54.0 44.7 56.9 43.0 43.0 40.0 38.0 Tetra Na 2.05 5.045 3.85 3.85Pyrophosphate, Anhydrous Tetra Potassium 6.38 Pyrophosphate (60% Soln)Na Acid 2.1 4.0 1.0 4.3 4.5 4.5 2.0 Pyrophosphate Mono Alkyl 3.5 6.7 3.53.5 Phosphate according to Example I Cocamidopropyl 3.5 Betaine (30%soln) according to Example II Titanium Dioxide 0.5 1.0 0.25 0.3 0.3 0.20.2 TiO₂/Carnauba Wax 0.6 0.3 Prills Xanthan Gum 0.6 0.4 0.45 0.7 0.30.3 0.3 0.3 Water QS QS QS QS QS QS QS QS QS

Example VI Improved Ethoxylated Mono Alkyl Phosphate Surfactant

Undesirable non-polar materials were extracted from ethoxylated monoalkyl phosphate (supplied by Rhodia) utilizing a high pressure carbondioxide to separate the non-polar materials from the ethoxylated monoalkyl phosphate. First, 45 ml of the surfactant was placed into a 100 ccprocessing bag. The bag was then engulfed by an additional 100 cc sampleprocessing bag filled with 6 mm glass beads. The bags filled with thesurfactant and glass beads were placed into a 100 cc sample processingvessel (200 C/10 kspi operation) of the SFE unit. The settings usedwere: 80° C. for the oven assembly and restrictor valve assembly. Thetank pressure with CO2 was brought to 750 psi and equilibrated for 10-15minutes. Then the pressure was set to 3500 psi and allowed to soak for10 minutes. After 10 minutes, the static/dynamic valve was opened andCO2 flow was maintained at a steady rate of 10 mL/min for 10 min.Alternating static soaking and dynamic flow steps were completed 10times at the same pressure and temperature conditions.

The extracted materials were then analyzed and the treated ethoxylatedmono alkyl phosphate surfactant was evaluated for taste and odor afterthe extraction and shown to be very mild, especially when compared withthe starting material. The undesirable materials identified as removedfrom the commercially supplied material are set forth in Table 9, below.

TABLE 9 ethoxylated mono alkyl phosphate - Pre and Post CO2 ExtractionSample Concentration of undesirable CO2 materials (ppm, μg/g) SampleExtraction Dodeca- Dodeca- Dodecyl # Description Conditions nal nolAcetate VIa DERMALCARE Untreated 94.3 6534.0 62.0 MAP L213/S VIbDERMALCARE Post - 75.6 5256.8 47.6 MAP L213/S Extraction 3500 Psi/80° C.Sample VIa shows the untreated surfactant had 94.3 ppm Dodecanal, 6534ppm dodecanol, and 62 ppm dodecyl acetate. After treating the surfactantin a batch CO2 process as described, the treated MAP sample VIbcontained a reduced dodecanal of 75.6 ppm, a reduced dodecanol of 5256.8ppm, and a reduced dodecyl acetate of 47.6 ppm.

Example VII Improved Amine Oxide Surfactant

Undesirable non-polar materials were extracted fromN,N-Dimethyldodecylamine N-oxide (amine oxide) surfactant (˜30% aqueoussolution), supplied by Sigma-Aldrich Corporation (St. Louis, Mo., USA),using the process steps shown in Example I, substituting the amine oxidefor the MAP L213/S. Additionally, a different rotary evaporator (modelEL131 supplied by BUCHI Labortechnik AG in Flawil, Switzerland) was usedfor removing residual EtOAc. During rotovap, a vacuum was also appliedvia rough pump (General Electric model SKC36PN435GX, Fort Wayne, Ind.,USA), which was controlled by manual adjustment of a clamp added to ateed in segment of hose between the pump inlet and rotovap. Vacuum wasincreased to the point where surfactant began gentle bubbling. Byapplying vacuum, the rate of residual EtOAc removal was significantlyincreased. The pre- and post-extraction amine oxide materials were thenanalyzed by immersion SPME GC-MS (Agilent model 7890 GC & model 5975Mass Spectrometric Detector, Agilent Technologies, Wilmington, Del.,USA), and the treated amine oxide surfactant was evaluated for taste andodor after the extraction and shown to be very mild, especially whencompared with the starting material. GC-MS analyses for this examplewere performed at a later time with newer equipment and the resultingretention times are slightly longer than for other examples. Theundesirable materials removed from the commercially supplied materialare set forth in Table 10, below.

TABLE 10 Results for Amine Oxide LLE treatment with EtOAc Control Reten-(Pre- Post tion extract) Extract Area Time Peak Peak Reduc- UndesirableMaterial (Min) Area Area tion (%) Decane 3.45 729450 0 100.0 N,N- 4.1985799292 0 100.0 Dimethylhydroxylamine Undecane 4.326 1.58E+08 0 100.0Undecene Isomer 4.613 2433592 0 100.0 Undecene Isomer 4.663 514924 0100.0 Undecene Isomer 4.696 4576558 0 100.0 Undecene Isomer 4.7313314628 0 100.0 Undecene Isomer 4.873 13478025 0 100.0 Undecene Isomer4.981 7185801 0 100.0 Dodecane 5.262 97542837 275259 99.7 DodeceneIsomer 5.517 1722855 0 100.0 Dodecene Isomer 5.564 256787 0 100.0Dodecene Isomer 5.594 1970807 0 100.0 Dodecene Isomer 5.637 1.34E+0820278565 84.9 Dodecene Isomer 5.686 1713571 0 100.0 Dodecene Isomer5.749 5157893 0 100.0 Dodecene Isomer 5.847 2337409 0 100.0 Tridecane6.079 60387770 0 100.0 Substituted Tetrahydrofuran 6.211 741293 0 100.0Tridecene Isomer 6.304 934388 0 100.0 Tridecene Isomer 6.373 2370074 0100.0 Tridecene Isomer 6.411 1509006 0 100.0 Tridecene Isomer 6.5145357518 0 100.0 Tridecene Isomer 6.61 2493787 0 100.0 Tetradecane 6.80888989028 0 100.0 Tetradecene Isomer 7.013 648872 0 100.0 TetradeceneIsomer 7.075 793547 0 100.0 Tetradecene Isomer 7.119 51889810 629899787.9 Methyl Tetradecane Isomer 7.184 1406294 0 100.0 Tetradecene Isomer7.209 1387502 0 100.0 Tetradecene Isomer 7.301 1082259 0 100.0Pentadecane 7.469 10662978 0 100.0 Unknown 7.683 3450057 0 100.0 Methyl4,6-decadienyl ether 7.863 19513653 0 100.0 Hexadecane 8.094 34907941 0100.0 Undecanone Isomer 8.166 258835 0 100.0 N,N-Dimethyl-1- 8.30476976187 228611 99.7 Dodecanamine Undecanol 8.381 5483997 0 100.0Dimethyl Undecanone 8.421 1533470 0 100.0 Dodecanone Isomer 8.582 3942390 100.0 Heptadecane 8.681 4445134 0 100.0 Dodecanone Isomer 8.783 5377290 100.0 Dodecanal 8.824 16858547 3586725 78.7 SubstitutedTetrahydrofuran 8.956 4420861 0 100.0 Methyl 6,8-dodecadienyl 9.05613713367 0 100.0 ether Octadecane 9.238 23859062 0 100.0 Dodecanoicacid, methyl 9.303 6560940 0 100.0 ester N,N-Dimethyl-1- 9.358 260948043499984 86.6 Tetradecanamine Tetradecanone Isomer 9.737 1458218 0 100.0Nonadecane 9.768 1489949 0 100.0 Unknown Amide 9.864 255865 0 100.0Tetradecanone Isomer 9.923 589980 0 100.0 Unknown Amide 10.048 341466 0100.0 Dodecanol 10.137 40526459 856635 97.9 Pentadecanone Isomer 10.2734602974 0 100.0 Methyl tetradecanoate 10.374 1435045 0 100.0Pentadecanone Isomer 10.451 1668318 0 100.0 Tetradecanol 11.128 98749280 100.0 N,N-Dimethyldodecanamide 12.113 44118371 65123 99.9p-Dicyclohexylbenzene 12.445 2523931 0 100.0 N,N- 13.048 14118245 67931295.2 Dimethyltetradecanamide Dodecanoic acid ester 14.154 24988729 0100.0 Dodecanoic acid ester 15.662 2168393 0 100.0 Avg % 98.9 Reduc-tion =

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “20 g” is intended to mean“about 20 g.” All percentages, ratios and proportions herein are on aweight basis unless otherwise indicated. Except as otherwise noted, allamounts including quantities, percentages, portions, and proportions,are not intended to indicate significant digits.

It should be understood that every maximum numerical limitation giventhroughout this specification includes every lower numerical limitation,as if such lower numerical limitations were expressly written herein.Every minimum numerical limitation given throughout this specificationwill include every higher numerical limitation, as if such highernumerical limitations were expressly written herein. Every numericalrange given throughout this specification will include every narrowernumerical range that falls within such broader numerical range, as ifsuch narrower numerical ranges were all expressly written herein.

Except as otherwise noted, the articles “a”, “an”, and “the” mean “oneor more”.

As used herein, “comprising” means that other steps and otheringredients which do not affect the end result can be added. This termencompasses the terms “consisting of” and “consisting essentially of”.The compositions and methods/processes of the present invention cancomprise, consist of, and consist essentially of the essential elementsand limitations of the invention described herein, as well as any of theadditional or optional ingredients, components, steps, or limitationsdescribed herein.

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A treated water-soluble surfactant compositioncomprising from about 10% to about 94% of water-soluble surfactant, fromabout 3% to about 90% water, and less than about 1% of undesirablenon-polar materials, produced by a process for improving the taste ofwater-soluble surfactants using liquid-liquid solvent extraction, saidprocess comprising the steps of: a) providing a water-soluble surfactantcomposition in need of treatment wherein said water-soluble surfactantcomposition comprises a water-soluble surfactant and one or moreundesirable non-polar materials; b) contacting said water-solublesurfactant composition with an extraction solvent and water to form anextraction mixture comprising an aqueous phase and a solvent phase; andc) separating the aqueous phase from the solvent phase; wherein theextraction solvent is selected from solvents having individual Hansensolubility parameters of a dispersion force component (δ_(D)) rangingfrom about 15 to about 17 (MPa)^(0.5), a polar component (δ_(P)) rangingfrom 0 to about 9 (MPa)^(0.5) and a hydrogen bonding component (δ_(H))ranging from 0 to about 11 (MPa)^(0.5).
 2. A treated water-solublesurfactant composition according to claim 1, wherein the surfactantcomposition comprises less than about 2% of undesirable non-polarmaterials.
 3. A treated water-soluble surfactant composition accordingto claim 1, wherein the water-soluble surfactant is at least about 20%soluble in water.
 4. A treated water-soluble surfactant compositionaccording to claim 1, wherein the water-soluble surfactant is selectedfrom anionic surfactants, zwitterionic surfactants, amphotericsurfactants, and mixtures thereof and is at least about 30% soluble inwater.
 5. A treated water-soluble surfactant composition according toclaim 4, wherein the water-soluble surfactant is selected from alkylphosphate surfactants, alkyl phosphate ethoxylated surfactants, laurylsulfate surfactants, betaine surfactants, betaine ethoxylatedsurfactants, amine oxide surfactants, and mixtures thereof.
 6. A treatedwater-soluble surfactant composition according to claim 1, wherein thesurfactant is selected from cocoamidopropyl betaines, alkyl ethoxylatedphosphates, mono alkyl phosphates, and mixtures thereof.
 7. A treatedwater-soluble surfactant composition according to claim 5, wherein thewater-soluble surfactant is an alkyl ethoxylated phosphate surfactant.8. A treated water-soluble surfactant composition according to claim 1,wherein the extraction solvent has individual Hansen solubilityparameters of a dispersion force component (δ_(D)) ranging from about 13to about 19 (MPa)^(0.5), a polar component (δ_(P)) ranging from about 2to about 9 (MPa)^(0.5) and a hydrogen bonding component (δ_(H)) rangingfrom about 2 to about 11 (MPa)^(0.5).
 9. A treated water-solublesurfactant composition according to claim 1, wherein the extractionsolvent is selected from ethyl acetate, water-saturated ethyl acetate,ethyl propionate, ethyl butyrate, ethyl pentanoate, ethyl caproate,ethyl caprylate, ethyl pelargonate methyl acetate, methyl propionate,methyl butyrate, short chain esters, supercritical carbon dioxide, andmixtures thereof.
 10. A treated water-soluble surfactant compositionaccording to claim 9, wherein the extraction solvent is selected fromfood grade ethyl esters.
 11. A treated water-soluble surfactantcomposition according to claim 10, wherein the extraction solvent isethyl acetate.
 12. A treated water-soluble surfactant compositionaccording to claim 1, wherein the extraction mixture comprises fromabout 10% to about 90%, by weight of the mixture, of water; from about5% to about 60%, by weight of the mixture, of water-soluble surfactant;less than 5%, by weight of the mixture, of undesirable non-polarimpurities; and from about 10% to about 90%, by weight of the mixture,of solvent.
 13. A treated water-soluble surfactant composition accordingto claim 12, wherein the ratio of extraction solvent to water-solublesurfactant in the extraction mixture is from about 1:10 to about 10:1.14. A treated water-soluble surfactant composition according to claim 1,wherein the step of separating the aqueous phase from the solvent phasefurther comprises centrifuging the extraction mixture.
 15. A treatedwater-soluble surfactant composition according to claim 1, wherein theprocess further comprises mixing the extraction mixture for a period offrom about 10 seconds to about one minute with vigorous mixing and atambient temperature before allowing the mixture to settle into twophases and separating the aqueous phase from the solvent phase.
 16. Atreated water-soluble surfactant composition according to claim 1,wherein the process further comprises the step of heating a solid impuresurfactant material to its melting point before the step of contactingwith an extraction solvent and water.
 17. A treated water-solublesurfactant composition according to claim 1, wherein the process furthercomprises the step of removing any residual solvent from the aqueousphase wherein the step of removing any residual solvent from the aqueousphase includes the use of an industrial method selected from vacuumstripping (with or without heat), fractional distillation, wiped-filmevaporator, carbon filtration, or combinations thereof.
 18. A treatedwater-soluble surfactant composition according to claim 1, wherein theextraction mixture further comprises a phase separation enhancerselected from salt, pH modifiers, and mixtures thereof.
 19. A treatedwater-soluble surfactant composition comprising from about 10% to about94% of water-soluble surfactant, from about 3% to about 90% water, andless than about 1% of undesirable non-polar materials, produced by aprocess for improving the taste of water-soluble surfactants usingliquid-liquid solvent extraction, said process comprising the steps of:a) providing a water-soluble surfactant composition comprising asurfactant selected from alkyl phosphate surfactants, alkyl phosphateethoxylated surfactants, and mixtures thereof and one or moreundesirable non-polar materials; b) contacting said water-solublesurfactant composition with ethyl acetate and water to form anextraction mixture comprising an aqueous phase and a solvent phase; andc) separating the aqueous phase from the solvent phase.
 20. An oral carecomposition having improved consumer acceptance, wherein the oral carecomposition comprises a water-soluble surfactant composition accordingto claim 1.